B) Currently, once coins are sent, they are pretty much gone, unless the recipient (seller) voluntarily returns the money.

C) Proposed solution:
01 - define two types of send functions: "final send" (FS) and "conditional send" (CS).
02 - FS = no change from current method of sending.
- CS = send to be conditioned upon the buyer (sender) being happy with his/her purchase; and
confirmed by a "confirmation key" (CK). The CK must be scanned / entered into the blockchain
prior to a certain block (time/suspense) in order for the funds to be fully
confirmed by the miners and/or masternodes.

D) Example: Parties: seller/recipient (Sam), buyer/sender (Bob, also Bob1, Bob2,..Bobn) and Carrier.
01) Sam lists a single product for sale.
02) Bob buys the product, (assuming only one bidder/buyer) and pays by conditional send (CS), with
suspense of X-days; results:
- a) product arrives via Carrier; Bob sees product and is happy to accept, he enters the confirmation
key (CK) prior to the X-day suspense, with Carrier acting as the person receiving the CK, which
serves as the signature equivalent. Carrier drops off product, and the confirmation key (CK)
allows the blockchain to confirm the original Conditional Send (CS) and Sam receives his coins.
- b) product doesn't arrive; product arrives late, defective or Bob doesn't sign off with confirmation key
(CK) before X-day suspense, then the original Conditional Send (CS) is NOT validated and NOT
sent; also Carrier does NOT deliver, and returns the product to Sam the seller.
03) Obviously, if more than 1-buyer is interested, then Sam will simply sell to the highest bidder; and this
becomes an automatic auction.

E) Details to consider: Carrier will need to have an app/wallet function to access the blockchain and enter key on behalf of Buyer. probably, many others ... that's just the nature of ideas & solutions. We can think these out. What do you guys think? Sweet? Simple? Possible? Hard? Easy? User friendly? Already done? I don't know the technicals, but I think this would really facilitate a more secure buyer experience.

Actually, it's the other way around: The Carrier needs to scan the Buyer's QR code for the Confirmation Key. This CK must be entered into the blockchain prior to its suspense time/block in order to lock in the Conditional Send. Once the CK is revealed (and this doesn't need to be revealed to the Carrier: it can be anybody including the Seller), it can be used to Confirm the prior Conditional Send.

Actually, I'm only asking if any developer out there would be willing to take a look and let us know how easy/difficult that would be. Once I have an idea, I would consider putting it up as a Dash proposal.
I wish I could do this myself, then I'd get it done! ;-)

I would be happy to return to my idea! I've been busy with other things, but I would be willing to promote this further, especially if there is community support. Also I'm not really sure how to get this idea in front of the developers and to see if they have any interest. Do you know how to set up a Dash proposal, where this might get some funding? I'm willing to donate some Dash for the devs to work on this.

Another use case --- Working Girls and Playing Boys:

Currently, the sex industry is rife with trespass, abuse, fraud, all things dangerous and rotten. I wish to see a more lawful ecosphere where voluntary exchange is made between consenting adults, more free from the coercion of third parties (pimps) and the unwarranted initiation of violence on the part of government. I believe Dash would be an ideal starting point to fundamentally change the field of play here -- especially if DOD (Dash on Delivery) can be implemented.

Current problems - Working Girls:
Working girls have to deal with the uncertainty of getting paid, possibly sharing her pay, and missing out on receiving the best bid for her time. In the last case, why would a working girl waste her time with a $100-payout, when someone else might offer her $500 for the same hour?

Current problems - Playing Boys:
The Boys are tired of texting for hours, waiting for a no-show. Or the girl shows up and is nowhere as hot as her ad. Either way, it's lots of wasted time, and knowing you got more to offer than the next guy just makes a man feel sad for all those struggling working girls out there.

Proposed Solution - Dash On Delivery:
Girl posts an ad, the Boys bid for her time by using Conditional Send (CS). The Girl picks the highest bidder, and they meet up within a pre-set time. If the girl misses her appointment, she ain't getting paid; or if she pretends to be someone she is not, then the Guy may have the option of not paying her. If the boy misses his appointment, then the girl has the option of responding to the next highest bidder. Either way, the guy's money is safe; and the girl is working at her fullest potential. These are additional advantages of using Decentralised Digital Cash in this field, because I believe DDC - Dash would also improve privacy, security and physical safety for all involved.

Loving it yet? You guys see the utility? So how do we get this off the ground?

DOD - Dash on Demand - for internet/mail order sales, and now for the World's Oldest Pastime!